Out of no where users of my forum started experiencing a redirect issue when logging in and out yesterday

[Staticfire]

When you login it brings you to the screen saying thank you for logging in and it begins to redirect you to the forum but then it just redirects you back to the login page.

If you go to domainame.com/forumname/forum.php you are logged in and able to post.

When logging out it says cookies cleared and then if you click the homepage you are still logged in.

I am running vBulletin 4.0.8 and this forum has no modifications and has remained unchanged for roughly 3 years with no issues ever occurring before.

I found some basic settings to check in a Google search but all of these settings are set correctly.

What in the world is making this happen?

I use this forum for business communications and this is completely unacceptable.

[Paul M]

Are you sure its not just you ?

Sounds very much like a browser cookie issue, delete all your cookies for the site, or try a different browser.

[Staticfire]

I am positive it is not just me. The issue was reported by the business owner and numerous employees and I verified the issue exits on 3 personal computers, my phone, and 2 work computers, and one of my coworkers computers.

[Paul M]

No idea then, ask whoever hosts your site what they have changed.

Things dont randomly start happening, something has to have changed, so if you havent changed anything, they probably have.

[Paul M]

I'm also wondering how you are running vB4 (even an old version) on a very old vB3 license.

[rcull]

Not to hijack a thread, but I have been having the same issue with 4.2.3 . It happens on all browsers, and it has come to my attention from forum users having problems. I tried logging out and it is almost impossible!
My host recently activated mod_lsapi, any chance that might effect it?

[Mark.B]

Anything that has been changed could have caused the problem. Ask them to revert the change and see if the problem goes away.